1. Field of the Invention
This invention relates to an electric operating apparatus for a vehicle, and more particularly to an electric operating apparatus for a vehicle in which a requested operation, such as a braking operation, is performed in accordance with a target pattern.
2. Discussion of Related Art
An electric operating apparatus for a vehicle in which a hydraulic power unit, an electric motor, etc., are operated in a predetermined manner by electrically detecting the depressing stroke of an operation pedal has been proposed, for example, in a service brake pedal apparatus used in a vehicle. The thus structured electric operating apparatus has a conventional problem in the fact that a driver accustomed to a conventional mechanical operating apparatus has difficulty in depressing a pedal because a depression reaction force is hardly generated by depressing the pedal although a reaction force is generated and applied by a return spring. Therefore, Patent Document 1 proposes a pedal reaction force apparatus in which a nonlinear depression reaction force that has hysteresis is given by use of a plurality of spring members and a damper, and Patent Document 2 proposes a technique according to which a variable pattern of a depression reaction force is changed by giving a pedal reaction force with a spring member and detecting an operating state, such as depressing speed electrically then moving the position of a spring bearing with an electric motor or the like.
[Patent Document 1] JP 2003-261015
[Patent Document 2] JP 2002-308084
However, in these conventional reaction force apparatuses, a reaction force is merely changed in accordance with a situation in which an operational member is operated, for example, in accordance with depressing speed, and no consideration is given to driving environments, such as road conditions, weather conditions, vehicular traveling speed conditions, and vehicle conditions, excluding a braking operation. Therefore, it is difficult to say that an appropriate braking force can always be obtained under various driving environments, and there is still room for improvement in allowing an easy operation so that even an inexperienced driver can always obtain an appropriate braking force. This problem exists not only in an electric braking operation apparatus but also in an electric operating apparatus, such as an accelerator pedal, for traveling requirements.
The present invention has been made in consideration of the foregoing circumstances, and it is an object of the present invention to provide an electric operating apparatus for a vehicle that can be easily operated so as to obtain an appropriate driving force and an appropriate braking force in various driving environments.